P CODE FAMILY

Powertrain code references — Page 40.

Engine, transmission and powertrain diagnostic references. Exact vehicle and module context still matters.

Toyota

P1129

These are code references, not a list of confirmed faults on every vehicle. Read the source and applicability notes, then match the exact vehicle, year, engine and scan report.

Electric Throttle Control System

Long Term Fuel Trim Bank 2 System Too Rich

HO2S Circuit Low Variance Bank 1 Sensor 1

Ford bank-one upstream oxygen switching has reached a fuel-control limit

Air/Fuel Ratio Sensor Circuit Range Performance Malfunction Bank 1 Sensor 1

HO2S Bank 1 Sensor 1 Not Switching Fuel Control Limit Reached

Swirl Control Valve Control Solenoid Valve

Front Oxygen Sensor Circuit Malfunction Open Circuit

Air/Fuel Sensor Circuit Range Performance Bank 1 Sensor 1

Long Term Fuel Trim Bank 2 System Too Lean

HO2S Circuit Low Variance Bank 1 Sensor 2

Ford bank-one upstream oxygen signal remains lean without switching

HO2S Bank 1 Sensor 1 Signal Below 0.45v AF Ratio Too Lean

Front Oxygen Sensor Circuit Malfunction Short Circuit

Bank 2 Sensor 1 Resistance Too High

O2 Sensor Heater Control Circuit Bank 1 Sensor 1

H02S Circuit Low Variance Bank 2 Sensor 1

Ford bank-one upstream oxygen signal remains rich without switching

HO2S Bank 1 Sensor 1 Signal Above 0.45v AF Ratio Too Rich

HO2S Circuit Low Variance Bank 2 Sensor 1

Oxygen Sensor Heating Circuit Bank 1 + 2 Sensor 1 Short To B+

O2 Sensor Heater Control Circuit Bank 2 Sensor 1

Bank 1 oxygen-sensor switching is evaluated over a qualified window

Bank 1 Fuel Control Shifted Lean

Air/Fuel Ratio Sensor Circuit Response Malfunction Bank 1 Sensor 1

Air/Fuel Sensor Circuit Response Bank 1 Sensor 1

Oxygen Sensor Heating Circuit Bank 1 + 2 Sensor 1 Electrical Malfunction

O2 Sensor Heater Circuit Signal Intermittent Bank 1 Sensor 1

Rich-to-lean and lean-to-rich transition times differ

Bank 1 Fuel Control Shifted Rich

Front Oxygen AF Sensor Microcomputer Problem

Oxygen Sensor Heating Circuit Bank 1 + 2 Sensor 2 Short To B+

O2 Sensor Heater Circuit Low Voltage Bank 1 Sensor 1

HO2S Lean Average Bank 1 Sensor 1

Pedal Position Sensor A Circuit Intermittent

Lexus RX300 front A/F sensor heater fault

HO2S Bank 1 Sensor 1 Heater Circuit Low Input

Intake Valve Timing Control Circuit Bank 2

Air/Fuel Sensor Heater Circuit Response Bank 1 Sensor 1

Oxygen Sensor Heating Circuit Bank 1 + 2 Sensor 2 Electrical Malfunction

O2 Sensor Heater Circuit High Voltage Bank 1 Sensor 1

HO2S Rich Average Bank 1 Sensor 1

Control Box Fan Circuit

HO2S Bank 1 Sensor 1 Heater Circuit High Input

Volkswagen additive lean trim: look beyond obvious vacuum hoses

O2 Sensor Heater Circuit Signal Intermittent Bank 1 Sensor 2

HO2S Bank 1 Sensor 2 Lean Or Low Voltage

Ford bank-one downstream oxygen channel does not respond lean as expected

Lack Of HO2S12 Switches Sensor Indicates Lean

HO2S Bank 1 Sensor 2 Not Switching Fuel Control Limit Reached

Front Oxygen AF Sensor Circuit Range Performance Problem

Long Term Fuel Trim Add Fuel Bank 1 System Too Rich

O2 Sensor Heater Circuit Low Voltage Bank 1 Sensor 2

HO2S Bank 1 Sensor 2 Rich Or High Voltage

Ford bank-one rear oxygen signal remains rich during its response check

Lack Of HO2S12 Switches Sensor Indicates Rich

HO2S Bank 1 Sensor 2 Signal Above 0.45v AF Ratio Too Rich

Long Term Fuel Trim Add Fuel Bank 2 System Too Lean

O2 Sensor Heater Circuit High Voltage Bank 1 Sensor 2

HO2S Insufficient Switching Bank 1 Sensor 2

Water In Fuel Indicator Circuit Malfunction

Front Oxygen AF Sensor #1 Heater Circuit Performance Range Problem

Volkswagen bank 2 additive rich trim and the purge-system connection

Mass Or Volume Air Flow Circuit Range Performance Problem

HO2S Transition Time Ratio Bank 1 Sensor 2

Water In Fuel Condition

Load Calculation Cross Check

Intake Valve Timing Control Position Sensor Bank 1

Bank 2 Sensor 2 Resistance Too High

HO2S Bank 1 Sensor 2 Average Voltage Level

Fuel Restriction Indicator Circuit Malfunction

HO2S Bank 1 Sensor 2 Heater Circuit Low Input

Mass Air Flow Sensor Circuit High Input

Volkswagen load calculation plausibility and the airflow cross-check

Fuel Restriction Condition

HO2S Bank 1 Sensor 2 Heater Circuit High Input

Mass Air Flow Sensor Circuit Low Input

Volkswagen lower load-cross-check limit and the two throttle signal pairs

HO2S Bank 1 Sensor 3 Lean Or Low Voltage

Air Assisted Injector Control Valve Range Performance